Chuck operating mechanism for machine tools



July 1931. E. P. BURRELL ETAL 1,816,209

CHUCK OPERATING MECHANISM FOR "ACHINE TOOLS Filed April 10. 1928 9Sheets-Sheet l 311061113113 Wflwa I R 7 WWW.

July 28, 1931. E. P. BURRELL ETAL 1,816,209

CHUCK OPERATING MECHANISM FOR MACHINE TOOLS Filed April 10, 1928 9Sheets-Sheet 2 July 28, 1931. E. P. BURRELL ETAL I 1,316,209

CHUCK OPERATING MECHANISM FOR MACHINE TdOLS Filed April 10. 1928 9Sheets-Sheet a July 28, 1931. v E. PL BURRELL E-TAL 1,816,209

CHUCK OPERATING MECHANISM FOR MACHINE TOOLS n I k I I' L w I I m I v I Y.l l, I I a gwueptoz WKM y 8. 1931. E. P. BURRELL ET AL 1,815,209

CHUCK OPERATING MECHANISM FOR MACHINE TOOLS Filed April 10. 1928 9Sheets-Sheet s N K k. g g

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' (Q g N "i g n 6 k v gwwntoz $6 7211i #6 MT mmmv July 28, 1931. E. P.BURRELL ET AL 1,316,209

CHUCK OPERATING MECHANISM FOR MACHINE TOOLS Filed April 10, 1928QSheets-Sheet 6 a if r s I f i ,I 11km l1 \\\\x\\m\\\\ July 28, 1931. vE. P. BURRELL ET AL CHUCK OPERATING MECHANISM FOR MACHINE TOOLS FiledApril 10. 1923 9 Sheets-Sheet 7 'G mleniors Wav /wk &4 R I w M M July28, 1931. E. P. BURRELL ETAL. 0

CHUCK OPERATING MECHANISM FOR MACHI I IE TOOLS Filed April 10, 1928 9Sheets-Sheet 8 Jrwen tors Mwwvf gz July 28, 1931. E. P. BURRELL ET AL1,316,209

I CHUCK OPERATING MECHANISM FOR MACHINE TOOLS Filed April 10, 1928 9Sheets-Sheet 9 l atented July 28, 1931 UNITED STA TES PATENT OFFICEEDWARD P. BURRELL AND FRED nnocumm, or CLEVELAND HEIGHTS, OHIO,ASSIG-NOES TO THE WARNER-a SWASEY COMPANY, or CLEVELAND, OHIO, ACORPORATION OF OHIO Application filed April 10,

This invention relates to power operated mechanism for closing andopening chucks which are adapted to grip work pieces while the same arebeing machined; The present invention, while applicable to chucksgenerally, has particular advantages in connection with largechucks, theclosing and opening of which require a great amount of powerand whichcan be closed and opened manually only with great difficulty and with aconsiderable loss of time. f

The principal object of the present invention is tofprovide a poweroperated chuck closing mechanism by whichfthe chuck may be closed andopened quickly and safely.

A further object is to provide a mechanism of this character by whichthe movement of the chuck operating member, whether in the form of awrench or pinion, into and out of engagement with the chuck as well asthe rotation of this member are controlled by a single controlling leverwhich is capable of movements of difi'erent kinds or indifferentdirections to effect successively, first, the engagement of the-memberwith the chuck and then its rotation in the closing or opening operationandthen the stopping of this member and thewithdrawal of it from thechuck.

-A furtherobject is to provide an efiective form of interlock betweenthe controlling lever above referred to and the'controlling lever forthe chuck rotating mechanism so that it will be impossible either toengage the rotary endwise movable chuck opening and closing member withthe, chuck while the latter is in rotation and also impossible to startthe chuck into rotation while itis engaged with said member.

An additional object is to provide a control mechanism for the chuckclosing and opening member,-this mechanism being so arranged andconstructed that it will be impossible to start the rotation of thismember untilit is in full engagement with the part or parts of the chuckwhich the member is adapted to engage and actuate.

Still further'the invention aims to provide an automatic brake for thechuck with an operative connection between it and the control lever forthe chuck rotating mecha-' nism such that a brake is released when theCHUCK OPERATING MECHANISM FOR MACHINE TOOLS 1528. Serial No. 268,911.

control lever is moved from its neutral or inoperative position ineither direction to o1 )-erat1ve position controlling the rotation ofthe chuck in one direction or the other, and, further, so that the brakeis automatically applied when the control lever is moved from either ofits operative positions to or toward neutral position. I

Still further the invention aims to provide an effective combinationbetween the con trol lever. for the chuck driving mechanism, the controllever for the chuck closing and. opening mechanism and this brake bywhich the interlock between the two levers is obtained and by which thebrake is released or automatically applied when the control lever forthe chuck driving mechanism is shifted. The above and other objects areattained by the present invention which may be here briefly summarizedas consisting in certain novel combinations and arrangements of, partsand details of construction which will be described in the specificationand set forth in the appended claims.

In the accompanying'sheets of'drawings we have shown one embodiment ofthe invention wherein the mechanism involved in the invention is theform of an attachment to the headstock and bed of a lathe, the power foroperating the chuck closing and opening member being'obtained from theheadstock and in this instance being connected to one of the gearsutilized in rotating the work spindle and chuck. However, the invention-may be used to advantage on other types of machine tools and is notnecessarily connected to or operated by the power means for rotating thework spindle, nor is it necessary that the mechanism be in the form ofan attachment to a machine tool as it may be built into the same soas toform an integral or permanent part thereof.

In the accompanying sheets of drawings, Fig. 1 is aside elevation of thehead and chuck to which the mechanism is applied andshowing a portion ofthe bed; Fig. 2 is a view of the same looking toward the front of thechuck, the bed being in section; Fig. 3 is a plan view of the mechanismshown in Fig. 1; Fig. 4 is a View partly in elevation but prinforgripping work pieces.

cipally in section along theline l l of Fi 3; Fig. 5 a view of themachine and mechanism shown in the preceding views but looking towardLthe head from the rear side of the machine, parts being in elevation butthe major portion in section the line 55 of Fig. .3; Fig. 6 is afragmentary sectional view substantially along the line 66 of Fig. ft;Fig. 7 is a similar view showing a modification in l. in the chuckclosing and opening member; Fig. 8 is a view partly in plan and partlyin horizontal section she-i detach-ed the con trol mechanism for thecruck operating member; Fi 9 is a side elevation of the same with partsin section, the main control lever being in one of its operativepositions and i thc actu tion of the conthereby prevcutins trol mcchai.for the ch lCl-i clos ng and opening memoer; Fl i0 is a view lookingtoward the left of F 8 with parts in. section and showing' portion ofthe attachment not shown in Fig, Q; Fig. 11 1S 4. other a fragmentary*cw of a part of the control mechanism li fated in Fig. 9 torshow theparts in a di' position than in Fig. 9, this view showi the main controllever in its central or neural position. permitting the operation of thecontrol meehanismforthe chuck closing and posing device; F] 12 is anenlarged plan View showing a portion of the mechan sm illi ted in Fig;8, this view indicatiz" 7 f ill 1 and by dotted. lines several p. thcontr hanisi' and opening n'uinher; 13 is View sh owing the support orthe main control lever and certain portions whi view lookin steward thehead; of the machine in front of it emoved nd \Vle'll he i showingd=iagra1nma'cthe mechani m b from --iistrati-n r particularly wh.

rotary work spindle to the forward end of which is applied a workholding chuck 23 adapted to support the work wl it is being machined.The work holding member need not be in the form. of what k,

chuck, but for the sake of brevity and con.-

venience of (T cription, thr ughout the specification, it Wlll bereferred to as a chuck.

Generally, however, the work holding memher is in the form of a chuckwhich may be of standard form or it may be special chuck In eitherevent,

form of the chuck and w n forming a aart of l e for the chuck closing chit operates, this section: and F 1.4]: a.

we have a of the bed of a lathe of which mounted the;

is generally known as a it generally has work gripping jaws which areradially movable.

Regardless of whether a special or standard form of chuck is employed,the body of the chuck is preferably surrounded by a stiff annulus 24which may be in the form of a casting, which preferably supported on andclamped to the ways of the bed, as best shown in Fig. 2. This annulusforms a support for themajor portion of the mechanism constitutingthepresent invention.

in Fig (3 whore-in we have shown special form of chuck, the innerpart ofthe annulus 24 is arranged closely between two flanges 25 of the chuckbody, there being a slight clearancebetween the inner periphery of theannulus and the corresponding surface of the chuck body, the chuckhaving no supporting DIQCl to a part of a rotary and endwise-mov- ,semovementmovingare in the positions shown in Fig. 6, these ts are intheir normal moperatwe posiand chuck body so that the latter may berotated without 1nterference by the gear.

It will be understood that each set of aws.

26 is moved by one set of wedges adapted. to be shifted by one of thescrolls, one set of wedges being adapted to slide in one direction,while the other of wedges is adapted to'slide in the opposite direction,the twosets being THOFGCl in opposite directions by the two oppositelyrotated scrolls, as more fully described in a prior application SerialNo. 229; S96. filed October 31, 1927.

In Fig. 7 wehave shown a standard form of chuck wherein the chuck body23a has one set of radially movable jaws 26a Wiich are moved in. thewell-known manner by a scroll indicated at 2864, this scroll beingrotated by any one of a series of pinions 28b, arrange-d an equaldistance apart about the periphery of the chuck body. Each pinion has asquared socket adapted to be engaged by the chuck operating: member herein the form of a wrench 29a which is carried by the rotary and endwisemovable shafts 3064 similar to that shown in Fig. 6. The wrench 29a isshown in 7 withdrawn from the pinion 28b-so that the chuck is free torotate without interference by the wrench.

has two sets of jaws or work.

opposite directions, this gear 29 being gear 29 into and out ofengagement with: scrolls. lVhen the shaft 30-and the gearus, the gearthen being clear of the scrolls may be employed with the mechanism constituting the subject matter of the present invention.

The work spindle 22 and, therefore, the

chuck are adapted to be rotated by a train ofmechanismcontained in thehousing 31 of the headstock and this mechanism may be driven by anysuitable source ofv power such as a motor or a belt pulley 32, indicatedin Fig. 14, which may be rotated at a constant speed not only to operatethe work spindle but also to actuate the tool carrying members whichwill be supported on the bed in the usual or well-knownmanner.

The endwise and rotatable shaft which carries the chuck closing andopening member, such as the gear 2901 the wrench 29a, is

'in this instance arranged laterally ,of the chuck and substantiallyhorizontally on the rear side of the chuck or on the rear side of thelathe, assuming that the chuck is applied to the work spindle of alathe." This arrange ment of the shaft and of the-mechanism foractuating it on the rear side of the machine rather ahan onthe front oron the top of the machine has the important advantage that it leaves thefront and the top portions of the machine substantially clear of thismechanism so that it does not interfere with other working parts of themachine, such as a motor or other attachments.

The shaft 30 carrying the chuck operating 1 member is supported alongwith other mechanism in a casing 33 which is bolted to a pad on the rearside of the annulus 24 as very clearly illustrated'in Figs. Qand 4. Thisshaft is adapted to be shifted in an endwise direction by .mechanism tobe referred to presently and it is adapted to be rotated in bothdirections, one dlrection of rotation being for shifting the jaws orwork gripping means into engagement with the work piece and the otherfor shifting the work "ripping means in the opposite direction away fromthe work piece. In this instance, the power for rotating the shaft 30 isderived from a gear 34 (see Figs. 13 and 14) forming one of the spindledriving gears of the headstock, this being a constant speed gear whichis rotated long as the pulley 32 is rotated or as long as the equivalentof the pulley' such as the motor is in operation. That is to say, therotation of the gear 34 is unaffected by the stopping of the workspindle, which is controlled by a clutch arranged at a suitable pointbetween this gear and the work spindle. In this instance, power is takenfrom this gear through the rear side of the. headstock to which isapplied a casing 35 supporting two gears 36 and 37, (see Figs. 5, 13 and14), the latter being an idler gear arranged betweenthe gears 34 and 36.The gear 36 is .mounted on a shaft 38 one end of which is the clutchgear 54.

supported in the casing 35which connected by a'coupling-39: (see Figs. 5and 14) to a shaft 40 which'is supported by a housing 41 which issecured to the side of the housing 33 which, as before stated, supportsthe shaft 30 and is secured to the rear sideof the annulus 24. Thisshaft 40 is connected by three gears 42, 42a and 42b to a shaft 43extending into the housing 33, the said gears being of a variable ratioto suit different driving speeds of the chuck operating member and beingof variable diameters to permit different displacements of shafts 40 and43 to accommodate chucksof different sizes and to admit of the unit,including the housing 33, to be moved inward or outward in accordancewith the size of the chuck.

The shaft 43 is provided on its inner end within the housing 33 with abevel pinion 44 which meshes with a bevel gear 45 forming one element ofa slipping clutch which is clearly illustrated in Figs. 4 and 14. Thisslipping clutch is arranged on a shaft 46 and consists, in addition tothe bevel gear 45 which may rotate freely on shaft 46, of a frictionclutch member 47 which is held in engagement with the gear 45 underpredetermined pressure by a coil spring 48 surrounding a portion of theshaft 46 and engaging an {H-- justable abutment in tile form of a nut 49secured onto snaft 46, the clutch member 47 being keyed to shaft 46 butslidable thereon. This slipping clutch located in the drive be tween theheadstock and the shaft carrying On shaft 46 is provided a pinion 50enif gaging a wide faced pinion 51 on a shaft 52 supported by thehousing 33. From this pinion and shaft 52 power is transmitted to shaftits 30 to rotate the same in opposite directions through two clutchgears 53 and 54 which are supported in the housing 33, and havesleeve-like extensions which form supports for shaft 30. The drive takesplace direct from pinion 51 to clutch gear 53 to rotate I the shaft 30in one direction and the drive from pinion 51 to clutch gear 54 forrotating shaft 30 is through two idler gears 55 and 56 (see Fig. 14) ona shaft 57 also supported by the housing 33, the idler gear 56 engagingEither clutch gear 53 or to the shaft 30 by a movable clutch member 57which is splined to shaft 30 so as to r0- tate therewith and is adaptedto be shifted lengthwise thereof between the clutch gears 54 may beclutched 53 and 54 by a shifting lever 58 (see Figs. 4 and 10), which isoperated as will be explained presently. It might be here stated.

that the clutch gears and the opposite ends of the clutch member 57 areprovided with clutch teeth which come into engagement so as to transmitmo ion from one or the other of the clutch gears to the clutch member57, the teeth being spaced apart so that a hammer blow va'i" be impartedto the clutch member and therefore to the shaft 30, this being ofespecial importance in the opening operation, and it is useful. also inthe closing operation when an exceptionally strong gripping is desired.

The shaft 30 is adapted to be moved in an endwise direction, in whichevent it slides through the clutch gears 53 and 54 and movable clutchmeml'ier 57, by means of a shifting lever 59 (see Figs. 4;, 6 and 7)having shoes engaging a shoe ring 60 formed on the shaft. The manner inwhich this lever 59 is controlled and shifted will also be e plamcdpresently.

The main control lever which controls the rotation of the work spindleand chuck in the lever is shown in its neutral position, and

to cause the work spindle and chuck to be rotated in one direction it isswung from neutral position. in one direction and vice versa. T is maincontrol lever controls a main control clutch including a movable clutchmember designated by the reference character 62 in Fig. 1%, which clutchmemher is shown on a. clutch shifting member 6264 provided with a shoering 62?) which is adapted to be moved back and forth by a lever 628(see Fig. 13) the main control lever is rocked. This lever is connectedto a vertical rock shaft 62d to which the main control lever 61 isconnected. This clutch member 62 is adapted to clutch either of twogears 63 and 64. to a shaft 65, the gears 63 and (54 being rotated inopposite direc tions by the constant speed gear 34: through gears 34a,indicated in Fig. 14. In this instance the shaft 65 carries a slidinggear cone 66 by which any one of a plurality of speeds may be impartedto the work spindle which provided with gears adapted to engage the earsof the cone. It will be understood t ntv we have not attempted to hidicate all of the gears and shafting employed in the usual headstock butthe showing of Fig. 1 will indicate a suitable driving connectionbetween the main source of power, in this case the pull y 32, and thework spindle for rotating the latter and the chuck in oppositedirections.

The chuck closing andopening mechanism is controlled by a lever 67 whichis also on the front side of the machine and which, like the lever 61,is supported on the top of the headstock. This lever 67 is capable oftwo distinct movements, one being a swinging movement in. plane at rightangles to the axis of the machine and the other being arockin'g'movement in a plane parallel to the axis of the machine. Thefunctions of these movements will be explained presently.

For the swinging movement, this lever is pivoted at 68 on a bracket 69which is, capable of rotating to permit the rocking movement of thelever. This bracket 69 is rotatahly supported on the substantiallytubular portion 70 of a support 71 which is attached to the top of theheadstock, this support consisting of an irregularly shaped casting" aswill be seen from Figs. 8 and 9. The upper end of the lever 67 ispivoted to a sea-ft 72 which is given an endwise movement when the lever67 is swun on the pivo tal 6S and is given a rocking movement when thelever is rocked by rotating the bracket This shaft extends across thetop of the headstock and at its rear end it provided with a pinion 73.and just forwardly of the pinion it is provided wi'h an.- nular teeth ora circular rack 7 i. l i hen the lever 67 is swung from neutral positionoutwardly, the shaft 72 moves inwardly and the effect of this is firstto rock a bell-crank 75 having at one end teeth engagine the circularrack 7 4 and the movement or this bell-crank shifts a rack 76. Thesecond and laer effect of the rearward movement of ft 72 to move thepinion into further engagement with a second rack 77. These two racksare supported in horizontal position, in the rear end of the supporting;memb r 71 (see Fig. 8) and in an upwardly projecting member 38a formingan extension of the housing i i/ hen the rack 76 is shifted, it rocks alever 78 which is fixed to the top of a vertical shaft 7 9 8) containedwithin a portion of the housing 33 and provided near its lower end withthe lever 59 (see Figs. (5 and 7) which is utilized in shifting shaft 30in. an endwise direction to bring the chuck operating member into or outof engagement with the jaw shifting part or parts of the chuck. Thefunction of the pinion 73 which is at all times in mesh with the secondrack 77 is to shift the clutch member 57' the pinion being rotated byrocking the lever 67 and bracket 69 thus turning the shaft 7:2 and thepinion Tl 30 is rotated depends upon the direction in;

rotate.

which the clutch member 57 isshifted, and, as will be apparent,theclutch member may be caused toengage either clutch gear 53 r .54,depending upon the direction inwhich the rack 77 is shifted, and this inturn depends upon the direction in which the control lever 67 is rocked.

It is of vital importance in order that breakage may be avoided, thatthe chuck closing, and opening member be in full engagement with the jaw shifting part of parts of the chuck before this member is permittedto Accordingly, it is important and vital to the success of'the poweroperated chuck closing and opening mechanism that the shaft 30 be givenits full endwise movement to engage the chuck operating member with thejaw shifting member or members of the chuck before the shaft is rotatedand that it be held in the engaged position and be prevented fromaccidentally or otherwise being moved out of engagement while the shaftis being rotated in either direction.

This makes necessary the provision of means for requiring the fullswinging movement of the control lever 67 away from neutral positionbefore it can be rocked in either direction, and after the chuck hasbeen closed, the completion of the rocking movement to place the clutchmember 57 in neutral position before shaft 30 is retracted. This isaccomplished in a simple but very effective manner by providing on theendwise movable and rocking shaft 72 a pin 82 which engages in a T-slot83 formed in a portion of the support 71. When the control lever 67 isin neutral position, the pin occupies the position in the slot shown inFigs. 3, 8 and 12 being at the front end of that portion of the slotwhich stands transversely to the axis of the machine.- When thelever 67is swung outwardly its full distance this pin is brought into line withthat portion of the slot which extends longitudinally of the axis of themachine, and, accordingly, when the pin occupies this position and notuntil then can the lever be rockedto cause the shaft 30 to be rotated inone direction or the other, the pin being shown in this position in Fig.11 and in Fig. 12 at 82a where'its position at such time is shown bydotted lines. When the pin has been moved to position 82a by the endwisemovement of the shaft 73 result ing in the endwise movement of shaft 30to cause the engagement of the chuck operating member with the chuck, it(the pin) may then be moved to either end of the slot to position 825 or820 shown in Fig. 12, when shaft 7 2 is rocked to engage the clutch mem-0 her 57 with one or the other of the clutch gears 53 and 54, it beingunderstood that when the pin is in position 82?), the clutch member 57is in engagement with one, clutch gear and when it is in position 820,the clutch member is in engagement with the "other clutch gear. Itfollows also that afterthe chuck has been closed or opened the pin mustbe brought back into alignment with the transversely extending portionof the slot resulting in the disengagement of the clutch member 57 fromthe clutch gear which it previously engaged and then the pin may bemoved forward to its normal position which is done by swinging thecontrol lever forwardly to its normal position indicated in Fig. 9. v

When the control lever 67 is in. its normal inoperative position, it ishighly desirable that the clutch member 57 be maintained in its neutralposition and that it be prevented from shifting accidentally orotherwise into engagement with either of the clutchv gears 53 or 54.This desirable feature is attained by our construction because of theconstant engagement of the pinion 7 3 with the teeth of the rack 77 forthe reason that the shaft 73 is held fronrrotating by the engagement ofthe pin 82 with the transverse portion of the T-slot 83 (the clutchmember 57 at such mechanism a brake for checking the rotation of thework spindle and chuck as soon as the lever 61 is thrown from eitheropera- ,tive position to neutral position thus permitting the operatorto open the chuck by operating the control lever as soon as a wor piecehas been completed, thereby'avoiding loss of time which would otherwisebe caused by the inertia of the rotating parts. Additionally, we providefor the automatic application of the brake and for the disengagement ofthe brake member from the chuck by the mere throwing of the lever 61,and we also provide an interlock between the main control lever 61 andthe lever 67 which controls the chuck closing and opening mechanismsothat it will be impossible for the operator to attempt to open orclose the chuck by inserting the chuck operating member on shaft 30 intothe chuck while the chuck is ro tating, and also impossible for theoperator to start the work spindle and chuck in rotation when the chuckoperating member is engaged with the chuck either during the chuckclosing or opening operation. Thus liability of breakage is avoided. Inthe accomplishment of these ends there is provided in the supportingmember 71 a horizontally arranged shaft 84 on which is mounted forslight rocking movement a wide faced lever toward the front side of themachine. Addidescribed above, we have provided as a part of ourimproved" tionally there is pinned or otherwise secured to this shaft acollar 89 l living forwardly projecting tongue 87 which is adapted toengage the lower end of an adjustable set screw 88 which carried by thelever a short distance to wardly of the shaft Additionally, there ispinned or otherwise secured, in till; 'nstance, to one end of shaft 84 alever 89 whicn extends from the shaft toward the rear side of theniacsiine an i carries a brake shoe 90 which in turn is adapted toengage a grooved portion 91 of the chuck body, his grooved portion beingadjacent the rear end, of the chuck as shown in Fig. 3.

The brake shoe is preferably pivotally connected to lever 89 by a pin 92so tl it may be adjusted to conform to the contour of the shoe engra ingportion 91 of tie chuck body. In this instance the shoe may be rockedaoout the pi- 92 and held in any desired position of adjustment by apair of set screws 93 extending through the lever and engagi the shoenear its opposite ends. 'lhe brake shoe is normally pressed agal t theshoe engaging portion 91 of the chuck body by means of a spring 94farranged between tie top of the lever and an adjustable abutment carriedby a screw 96 mounted in an ear 97 forming a part of the support 71.lVith this arrangement the action of the spring 94 is to normal ly tendto seat the brake shoe against the shoe engaging portion 91 of the chuckbody and at the same time to elevate to its upper most position, thewide faced lever 85 through the medium of the lip 87 and set screw 88.Obviously by adjusting the screw 88 it is possible to adjust therelative positions of the brake shoe lever 89 and the wide faced lever85. which adjustment may be advisable from time to time as wear on thebrake shoe occurs.

It will be observed that thelever 61 may be swung from neutral pos'jiOil shown in Fi 3 in either direction to cause the work spindle andchuck to be rotated in either forward or reverse direction. thisswinging movement of the lever taking place betweentwo elevated portions71a of the supporting mem ber 71 which portions are bridged by a crossplate 98 serving a guide plate for the lever 61. this plate ex himmediately over the lever 61 as lllUStl" in Figs. 1 3 but removed fromFi S, the upper side of the lever being a] imes in contact with thelower face of this plate. The lower side of the lever 61 is givenV-shape for a portion of its length, as best shown at 91a. in Figs. 1, 9and 11, and this l -shaped portion of the under side of the is adaptedto engage in a V-shaped notch 99 formen on the up side of the wide facedlever this eng ment taking place only when the lever is in neutralposition. It wil be observed that the front end of the wide fac d leverSo has an extension 100, one end of which projects over a portion of theT-slot 83 (see Fi 8), which is engaged by the pin 82 carried by theshaft 72 connected with the control lever 67, this extension beingpreferably in the form of a hardened plate attached to lever 85.

\Vhen the main control lever 61 is in neutral position'so that theV-shaped lower portion 61a thereof is directly in 'line with the slot 99provided in the wide faced lever 85, the

brake shoe 90 is engaged and the leveris held by the spring 9& in itsupwardmost position (see Fig. 11). At this time the extension 100 at theforward end of the lever lies above the pin 82 in the T-slot, thispermitting the pin to be moved under it, i. e., permitting free orunrestrained movement of the pin and, therefore, free or unrestrainedmovement of the control lever 67 for the chuck opening and closingmechanism. When the pin 82 is moved beneath the extension 100 of thewide faced lever 85, as shown in Fig. 11 at 82c, it is obvious that thelever 85 cannot be depressed by movement of the main control lever 61.

lVhen the pin 82 is in its normal position at the forward. end of theT-slot, i. e. out from beneath the extension 100 of the lever 85, andwhen the main control lever 61 is swung in either direction from neutralposition as shown in Figs. 1 and 9, the V-shaped portion or" the leverof course rides out of the "ll-shaped notch 99 of the lever 85 and thiscams the lever 85 downwardly, lifting the brake shoe from the shoeengaging portion 91 of the chuck body and it will be apparent that aslong as the lever 61 is out of neutral position the brake shoe will beheld out of engagement with the shoe engaging portion of the chuck body.lVhen the lever 61 is swung from neutral position, as just explained,thus causing the spindle and chuck to be rotated .in one direction oranother (depending .of course upon which direction the main controllever has been swung from neutral position) the extension 100 of thelever 85 is by such movement of the lever cammed downward so asto lieimmediately behind the pin 82, as best shown in Fig. 9, so that as longas the lever is out of neutral position it will be impossible for theoperatorto shift the control lever 67 to throw into operation the chuckclosing and opening mechanism.

As previously stated, ii the pin 82 is beneath the extension of thelever 85, it is impossible for the operator to shiftthe main controllever 61 from neutral position and thus impossible for him to start thework spindle and chuck into operation and to lift the brake from thechuck body as long as the chuck opening and closing mechanism is inoperation or as long as the chuck operating member of this mocha nism isin engagement wi h the chuck. In fact, with our improved mechanism it isimpossible to shift the main control lever from its neutral positionuntil the chuck operating member on shaft is withdrawn to its normalposition in which event the control lever 67 is in neutral position andthe pin 82 isin the forwardmost portion of the T-slot. It will be seentherefore that by this mechanism complete safety is provided.

While we have shown the preferred construction, we do not desire to beconfined to the precise details shown but aim in our claims to cover allmodifications which do not involve a departure from the spirit and scopeof our invention.

Having thus described our invention, we claim:

1. A machine tool having a driven member for rotating the work, adriving member for rotating the driven member in opposite directions, abrake for checking the rotation of said driven member and engaging thesame, a control member for controlling the rotation of the drivingmember in both directions and movable in either direction from neutralposition, and a a connection between the control member and said brakearranged to cause the brake to be released when the control mem ber ismoved from neutral position to operative position in either directionand to be applied when the control member is moved back to neutralposition. i

2. In combination with a machine tool having a heacstock containing aspindle adapted to be rotated in either direction, a chuck mounted onthe spindle, a brake arranged to engage a portion of the chuck, acontrol lever v for controlling the rotation of thespindle and movablefrom normal inoperative position in either direction, and a connectionbetween the control lever and the brake whereby the brake isautomatically applied when the control lever is moved to normal positionand is released from the chuck when the lever is moved from normalposition in either direction.

3. In combination with a machine tool having a headstock provided with aspindle adapted to be rotated in either direction, a lever movable ineither direction from normal position to control the rotation of thespindle, a chuck on the spindle, a brake member engageable with aportion of the chuck, and

\ toward and from the work holder. and acontrol member movable in onedirection to cause said rotatable member to engage the work holder andmovable in another direction to cause its rotation toshift the workengaging means.

5. In combination with a work holder having work engaging means, powermeans for shifting the work engaging means and including a rotatablemember movable into and out of engagement with the work holder, and acontrol member movable in an endwise direction to cause the engagementof said device with the work holder and rotatable to cause said memberto be rotated to actuate the work engaging means.

6. The combination with a work holder having work engaging means, ofpower means for shifting the work engaging means and including a memberrotatable in either direction and movable into and out of engagementwith the work holder, and a control member" mounted for movement in anendwise direction to cause said first named member to engage ordisengage the work holder and rotatable in either direction to causesaid member to be rotated to shift the work engaging means.

7. In combination with a rotatable work holder having work engagingmeans, a drive for said work holder, a control member for the drive bywhich the rotation of the work control member movable to shift saidrotatable member relative to the work holder and to control itsrotation, and an interlock between the two control members.

8. In combination with, a rotatable work holder having work engagingmeans, a drive for said work holder, a control member for the drive,means for shifting the work engaging means and including a rotatablemember movable into and out of engagement with the work holder, acontrol member for causing said device to be moved relative to the workholder and to be rotated, and an interlock between said control membersso as to prevent the engagement between said rotatable member and thework holder unless j the first mentioned control member is ininoperative position. e

9. In combination with a rotatable work holder having work engagingmeans, a drive for said holder, a control member for the drive havingoperative and inoperative positions, means for shifting the workengaging means of the work holder and including a rotatable membermovableint-o and out of engagement with the work holder, a drivetherefor, a control member for controlling both the rotation of saidrotatable member and its movement toward and from the work holder, andan III-e terlock between said control members which prevents theoperation of the first control the operation oi the unless the firstcontrol member is in mop-- member unless the second control member is inneutral position.

for, a cont ol member for controlling both the rotation said rotatablemember and movement toward. and from the work holder, and an interlockbetween said control member which prevents the operation of the firstcontrol member unless the second control member is in neutral positionand prevents second control member erative position.

11. In combination with a holder having work engaging means, a brake forchecking the movement of the work holdor, a drive for the work holder, acontrol member for said drive and brake, and means for shifting the workengagii'ig means of the work holder and having a control memberinterconnected with said first named control member.

12. In combination with a rotatable work holder having work engagingmeans, a power drive for the work holder, a brake for checking therotation of the work holder, a control member controlling both the powerdrive and the brake, means for shifting the worker.- gaging means andincluding a rotatable member movable toward and from the work holder, acontrol member movable in two directions to control the engagement ofsaid rotatable member with the work holder and also its rotation, andmeans forming an interlock between said control members.

In combination with a work holder having work engaging means, means forshifting the work engaging means and including a rotatable membermovable toward and from the work holder, and a control member at--ranged so that when firstv moved in an endwise direction it will shiftsaid member into engagement vith the work holder and when then rocked itwill cause the rotation of said member.

14. In combination with a work holder having work ens iging means, meansfor shifting the work engaging insane and including a roe in embermovable towarc from the work holder, a control member movable in anendwise direction to cause said member to be moved into engagement withth work holder and capable of rocking movement to cause said member tobe rotated, and means by which the control member i cons: rained to hefirst moved endwise before being rocked tor the work engaging operation.

Amaciinetooll aviag a bead provided rotatable work with a Work spindleadapted to be provided with a work holder having work engaging means, adrive in said head for the spindle and work holder, and power means forshifting the work engaging means, said power means including drivingmeans and a member arranged laterally 0t and movable substantiallyhorizontally relative to said driving means into and out of engagementwith the work holder.

16. Amachine tool having head pr vidcd with a work spindle, a drive forthe spindle, a chuck adapted to be applied to the spindle, power meansfor closing and opening the chuck and including a drive engageable withan element in the head and including also a member movable laterally onthe rear side of the head toward and from the periphery of the chuck.

17. The combination with a work holder having work engaging means, meansfor shifting the work engaging means and including operating membermovable to ward and from the work holder and also rotatable, a controlmember capable of two separate movements, one to cause the operat ingmember to be moved into or out of engagement with the work holder andthe other to control the rotation of said operating member, and devicesbetween the control member and the operating membe which are separatelyactuated by the two movements of the control member.

18. In combination with a work holder having work engaging means, meansfor shifting the work engaging means and including an operating membermovable endwise toward and from the work holder and rotatable in eitherdirection, a clutch for controlling its rotation, a control memberhaving two separate movements, a shifting means between said controlmember and the operating member to cause theendwise movement of theoperating member during one movement of the control member, and shiftingmeans between the control member and the clutch to cause the clutch tobe shifted during the other movement of the control member.

19. In combination with a work holder having work engaging means, meansfor shifting the work engaging means and including an operating membermovable in an endwise direction toward and from the work holder androtatable, a clutch for controlling its rotation, a shifter for movingthe operat ing member endwisc, control member having two separatemovements one for the endwise movement and one to control the rotationof the operating member, and operating means between said control memberand the shifter and between said control member and the clutch.

20. In combination with a work holder having work engaging means, meansfor shifting the work engaging means and including an operatlngmembermovable in an endwise direction toward and from the work holder androtatable, a clutch for controlling its rotation, a shifter for movingthe operating member I endwise, a control member havingtwo separatemovements one for the endwise movement and one to control the rotationof the operating member, and operating means between said control memberand the shifter and between said control member and the clutch, saidoperating means comprising a pair of racks, one actuated by one movementof thecontrol member and the other actuated by another movement of thecontrol member. "21.111 combinationwith a work holder having workengaging means, means for shifting the work engaging means and includingan operating member movable toward and away from the work holder andalso rotatable, a shifter for moving the operating member toward andfrom the work holder, a clutch for controlling the rotation of theoperating member, a control member having two separate movements, meansfor constraining the control member so that the part controlled by onemovement is locked against movement until the part controlled by theother movement isshifted.

22. In combination with a work holder having means for engaging a workpiece,

means for shifting the work engaging means and including an operatingmember movable toward and from the work holder and also rotatable, meanscomprising a control member movable in two directions to cause theoperating member to be moved toward or from the work holder and tocontrol its rotation, and means for preventing the movement of thecontrol member in one direction until its movement in the otherdirection is completed.

23. In combination with a work holder having means for engaging a workpiece,

means for shifting the work engaging means and including an operatingmember capable of a plurality of movements, means comprising a controlmember for controlling said movements, and means constraining saidcontrol member to cause one movement to be completed before another isinitiated.

24. In combination with a work holder having means for engaging a workpiece, means for shifting the work engaging means and including anoperating member movable in different directions, means comprising acontrol member for controlling said movements, and means for preventingboth movements being imparted at the same time to the operating memberby the control member.

25. In combination with a work holder having means for en aging a workpiece,

' means for shifting the work engaging means and including anoperatingmember, a shifter for moving the operating member toward having meansfor engagmg a work piece, I

means for shifting the work engaging means and including an operatingmember, a shifter for moving the operating member toward and frond thework holder, means comprising a latch for causing the operating memberto be rotated, a control member operatively connected with the shifterand clutch, and means for preventing the operation of the clutch untilthe shifter has been moved to cause the operating member to engage thework holder to'actuate the work engaging means.

27. In combination with a work holder having means for engaging a workpiece, means for shifting the work engaging means and including anoperating member, a shifter for moving the operating member toward andfrom. the work holder, means comprising a clutch for causing theoperating member to be rotated, a control member operatively connectedwith the shifter and clutch, and means for preventing the movement ofthe shifter to L disengage the operating member from the work holderbefore the clutch has been disengaged.

28. In combination with a work holder having work engaging means, powermeans for shifting the work engaging means, including an operatingmember movable into and out of engagement with the work holder and alsorotatable, a single control member for controlling both movements of theoperating member, a shifter and a clutch for said controlmemberoperatively connectedwith the control member, and means for preventingthe engagement of the clutch when the control member is in inoperativeposition.

1 29. In combination with a work holder having work engaging means,means for shifting the work gripping means and including'an operatingmember movable toward a shifter-and a clutch for imparting the movementsto the operating member, a control member having two separate movements,one for the shifter and the other for the clutch, a pair of endwisemovable members bea control member having two separate movements, onefor the shifter and the other for the clutch, a pair of actuatingmembers between the control member and the clutch respectively, andmeans connecting the control member with one of said actuating members,raid means including a pinion on the control member;

In combination with a Work holder having Work engaging means, means forshiftng the work engaging means and in cluding an operating membermovable toward and from the Work holder and also rotatable, a shifterand a clutch for imparting the movements to the operating member, acontrol member having two separate mover'nents; one for the shifter andthe other for the clutch, a pair of actuating member-she tween thecontrol member andthe clutch respectively, and means connecting thecontrol member with one of said actuating members, said means includinga rack on the control member.

32; Incombinationwith a Work holder having work engaging means, meansfor shifting the work engaging means and including an operating'n'iembermovable toward and from the W-ork'holdcr and also rotatable, a: shifter-and-a clutch for imparting themovements to the operating member,a-control member hav-' ing two separate movements, one for the shifterand the other for the clutch, a' pair of actu ating members between thecontrol member and the shifter and clutch respectively,

and means connecting the control member with sair'lactuating members, sid means in cluding a circular rack and a pinion on the control member.

33. In combination with a Work holder having means for engaging a Workpiece,-

power means for shifting the Work engaging means and including anoperating member having a plurality of separate movements, one forengaging the Work holder, and one for actuating the Work engaging means,and a single control member for causing said movementsto be imparted tothe operating member.

34. In combination with a Work holder having Work engaging means, meansfor shifting the work engaging means including an o ierating memberhaving a plurality of separate movements, one for engaging the worilrholder, and one'for' actuating'the work engaging means, and a singlemember for controlling said movements so as to cause" them'to beimparted successively.

A machine tool having a head provided 4 l with a Work spindle and adrive for the spindle, a chuck on the spindle, power means" forclos'ingand opening the chuck including a member movable laterally onthe rear side of the head toward and from the periphery of the chuck anda. control member therefor at the front side of the head.

36. A machine tool having a driven member including a chuck, a drivingmember for rotating said driven member in opposite directions, a brakefor checking the rotation of said driven member and chuck and adapt e toengage said chuck, a control member for controlling the rotation of thedriving 11 ember in opposite directions and movable in either directionfrom neutral position, and a connection between the control member andsaid brake arranged to cause the brake to be released when the controlmember is moved from neutral position to operative position in itherdirection and to be applied when the control member is moved back toneutral position.

in testimony whereof, We hereunto aflix 0 ar signatures.

EDWALRD BURRELL. FRED H. BOGART.

